The present invention relates to a hot water bag of a soft flexible material having a flat, in a plan view substantially rectangular configuration, and a filling neck projecting from a shorter side thereof. Conventionally hot water bags of this type are made of rubber. They may be provided on the upper surface thereof with ribs so that excessively hot water does not cause burning when the bag is in contact with the skin. To improve heat insulation it is known to enclose the rubber walls into a cloth covering. This measure however results in substantially increased manufacturing costs and in use it brings about an additional cleaning work.
It is an object of this invention to provide a hot water bag having an upper surface that is pleasant for contact with the skin.
Another object of this invention is to improve heat insulation of the bag.
Further object of this invention is to provide a hot water bag which can be manufactured at a low cost.
Still further object of this invention is to provide a hot water bag which can be easily cleaned.